Ok, so two things come to mind,

If the assessment / survey wasn't translated, you can follow the instructions here, if you have pre-translated everything as per the linked blog post, try doing a "cache.do" to ensure your browser has picked up all of the translations and to ensure you don't have a browser cache'ing issue.

If it's the smiley faces question type (image scale), then yes server-side it would be storing as numbers which would mean the labels are not necessarily translated (the "display_label" field should be of type "translated_text", meaning the translations would reside in [sys_translated_text]),

For sure worth going through my linked blog post to ensure the translations are present,

Many thanks,
kind regards